a+2b=3
b+a=2
a=?
B=?
a+2b=3
b+a=2
a=?
B=?a+2b=3
b+a=2
a=?
B=?a+2b=3
b+a=2
a=?
B=?a+2b=3
b+a=2
a=?
B=?a+2b=3
b+a=2
a=?
B=?a+2b=3
b+a=2
a=?
B=?a+2b=3
b+a=2
a=?
B=?a+2b=3
b+a=2
a=?
B=?
Mathematics
2008-04-05 4:05 pm
回答 (3)
2008-04-05 4:15 pm
✔ 最佳答案
a + 2b = 3 a = 3 - 2b ---------- (1)
b + a = 2 ---------------(2)
put (1) in (2)
b + 3 - 2b = 2
-b = -1
b = 1
b=1
b + a = 2
1 + a = 2
a = 1
參考: by myself
2008-04-06 12:15 am
a+2b=3----(1)
b+a=2----(2)
a=2-b----(3)
put (3) into (1)
2-b+2b=3
b=1
put b=1 into (1)
a+2(1)=3
a=1
b+a=2----(2)
a=2-b----(3)
put (3) into (1)
2-b+2b=3
b=1
put b=1 into (1)
a+2(1)=3
a=1
參考: myself
2008-04-05 4:29 pm
a+2b=3 (1)
{ b+a=2 (2)
由(1),a+2b=3
a=3-2b (3)
把(3)代入(2),
b+3-2b=2
b-2b=2-3
-b=-1(呢到因為題目問你b,not -b,so要將-b,chang to +b)
b=1
把b=1代入(1),
a+2=3
a=3-2
a=1
所以a=1,b=1.
{ b+a=2 (2)
由(1),a+2b=3
a=3-2b (3)
把(3)代入(2),
b+3-2b=2
b-2b=2-3
-b=-1(呢到因為題目問你b,not -b,so要將-b,chang to +b)
b=1
把b=1代入(1),
a+2=3
a=3-2
a=1
所以a=1,b=1.
參考: myself
收錄日期: 2021-04-14 20:37:42
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https://hk.answers.yahoo.com/question/index?qid=20080405000051KK00517